Remove a dead script in the CI directory (#3423)

This is no longer used on CI

ci/setup_centos6_python3.sh

@@ -1,34 +0,0 @@
-#!/bin/bash
-set -e
-
-VERSION=${1:-3.7.3}
-
-# Python 3.6 stands in our way -- nuking it
-yum erase -y rh-python36
-rm -rf /opt/rh/rh-python36
-
-yum install -y gcc bzip2-devel libffi-devel zlib-devel
-
-cd /usr/src/
-
-# pip3.7 needs new openssl
-curl -O -L https://github.com/openssl/openssl/archive/OpenSSL_1_1_1c.tar.gz
-tar -zxvf OpenSSL_1_1_1c.tar.gz
-cd openssl-OpenSSL_1_1_1c
-./Configure shared zlib linux-x86_64
-make -sj4
-make install
-cd ..
-rm -rf openssl-OpenSSL_1_1_1c
-
-# Fixing libssl.so.1.1: cannot open shared object file
-echo "/usr/local/lib64" >> /etc/ld.so.conf && ldconfig
-
-curl -O -L https://www.python.org/ftp/python/${VERSION}/Python-${VERSION}.tgz
-tar xzf Python-${VERSION}.tgz
-cd Python-${VERSION}
-./configure
-make -sj4
-make install
-cd ..
-rm -rf Python-${VERSION}